The Law of Attraction is such that whatever you give your attention to — positively or negatively — expands in your experience.
When you resist something you don't want, you're giving your attention to it, thus creating more of it.
For example, telling your child "This is a really important phone call, so DON'T interrupt me..." guarantees that you'll experience an interruption — if not by the child then by your own worrisome thoughts.
The key to creating more of what you DO want is to decide that you're free NOT to have it!
When you feel free either way, there's no resistance, which means you can focus on your desired experience.
Today, whenever you notice even a little tension about something, remind yourself of your inherent freedom. ("I'm free to be interrupted, or not.") Then gently shift your focus to your desire. ("I'm going to enjoy this call!")